Association between the administration of phenylbutazone prior to racing and musculoskeletal and fatal injuries in Thoroughbred racehorses in Argentina.

This research investigated the link between the use of phenylbutazone before a race and the risk of musculoskeletal and fatal injuries in Thoroughbred racehorses in Argentina. The study found that horses given phenylbutazone prior to racing had higher odds of both types of injuries, thus indicating a significant association and emphasising the need for more cautious medication policies to improve racehorse wellbeing.

Methods

• The study focused on Thoroughbred racehorses in 2 of the 4 official racetracks in Argentina, with races taking place between 2006 and 2015.
• Data on 283,193 race starts was gathered, with information relating to race performance and outcomes of injuries obtained from racetrack databases and veterinary reports.
• The researchers calculated the annual incidence of musculoskeletal injury (MSI) and fatal injury, differentiated by whether phenylbutazone was administered before the race.
• To identify significant risk factors for MSI and fatal injury, the team used univariable logistic regression. This was followed by multivariable logistic regression to control for the impact of other risk factors.

Results

• On analyzing the data, associations were found between the prerace administration of phenylbutazone and increased risk of both MSI and fatal injury while racing.
• Horses that received phenylbutazone before racing showed greater chances of sustaining an MSI (odds ratio or OR, 1.45; confidence interval or CI, 1.03 to 2.04]) and fatal injury (OR, 1.59; CI, 1.1 to 2.27) as compared to horses that were not medicated prior to the race.
• These associations held up when other risk factors were considered in the multivariable models.

Conclusions

• The results indicated a potential link between the administration of phenylbutazone before a race and the risk of MSI and fatal injury in Thoroughbred racehorses.
• Although these results do not necessarily mean that prerace administration of phenylbutazone directly causes injuries, they suggest its use as a significant risk factor.
• The findings of this study could support the development of conservative medication policies for racehorses in North and Latin America, aiming to enhance their welfare.